LONDON (AP) Liverpool went from dishing out a humiliation to being on the receiving end of one.

A 5-0 loss at Manchester City on Saturday handed Juergen Klopp his biggest loss in two years managing Liverpool. And it quickly punctured the optimism gathering around their English Premier League title challenge following a 4-0 victory over Arsenal before the international break.

Four of City's goals against Liverpool came after Sadio Mane was sent off for a high challenge that forced goalkeeper Ederson off injured in Manchester.

"I am not concerned in the long term," Klopp said. "It was hard for the boys but I don't look for excuses."

Jose Mourinho did after Manchester United's winning start ended in a 2-2 draw at Stoke , referencing the World Cup qualifiers over the last two weeks.

"My players, after the international break, are not the same," Mourinho said.

Chelsea's only setback so far came in an opening-day loss. The champions have been on the up since then, and a third successive victory was secured with a 2-1 victory over Leicester.

Arsenal quickly recovered from its misery at Anfield by beating Bournemouth 3-0. Danny Welbeck scored twice and Alexandre Lacazette also netted to leave the south-coast team winless after four games.

A couple of goal droughts ended.

Brighton scored its first top-flight goals in 34 years in a 3-1 victory over West Bromwich Albion.

Harry Kane, the league's top scorer last season, is off the mark as well for the campaign. The Tottenham striker netted twice in a 3-0 win at Everton , and Christian Eriksen also found the target.

Southampton's unbeaten start was halted by a 2-0 loss to Watford.

Pep Guardiola's side finally produced the type of imposing attacking display missing this season.

And the opening goal was a landmark one for Sergio Aguero. The Argentine striker's 124th Premier League goal since joining City from Atletico Madrid in 2011 made him the highest scoring non-European player in the competition's history.

"Sergio is crazy about the goal," compatriot Nicolas Otamendi said. "He's always in the right place at the right time."

And it came when the game was still 11 vs. 11. The City surge came after Mane received red.

Gabriel Jesus netted City's second in first-half stoppage time and again eight minutes into the second half. The Brazil forward was then substituted and his replacement, Sane, grabbed two goals as well.

"If City takes too much confidence from this game today, they make a mistake," Klopp said. "If we lose too much confidence because of this game we make also a mistake."

Chelsea had to single out its own fans for criticism after the reigning champions beat 2016 title winner Leicester. Some fans sang an anti-Semitic lyric about London rival Tottenham while celebrating Alvaro Morata, who headed in Chelsea's first goal.

N'Golo Kante also scored against former club Leicester.

United had scored 10 goals without reply in opening the title challenge with three wins. A reality check came with a trip to Stoke where Arsenal has already lost this season.

Eric Maxim Choupo-Moting became the first player to score against United this season. The Cameroon forward's opener was canceled out by Marcus Rashford in first-half stoppage time. After Romelu Lukaku put United in front, Choupo-Moting headed in Stoke's equalizer in the 63rd minute.

"Stoke are big, strong and powerful in the air," Mourinho said. "They fought hard and probably deserved a point."

And yet there wasn't a post-match handshake with Stoke counterpart Mark Hughes.

"I offered my hand but Jose didn't want to take it," Hughes said. "Maybe he was upset about the result. The top managers don't like it when they get the bad results. I have to get used to it sometimes."